/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: CurrentNodeListIterator.java,v 1.2.4.1 2005/09/06 06:04:45 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.dom;

import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;
import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;

/**
 * Iterators of this kind use a CurrentNodeListFilter to filter a subset of
 * nodes from a source iterator. For each node from the source, the boolean
 * method CurrentNodeListFilter.test() is called.
 *
 * All nodes from the source are read into an array upon calling setStartNode()
 * (this is needed to determine the value of last, a parameter to
 * CurrentNodeListFilter.test()). The method getLast() returns the last element
 * after applying the filter.
 *
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */

public final class CurrentNodeListIterator extends DTMAxisIteratorBase {

  /**
   * A flag indicating if nodes are returned in document order.
   */
  private boolean _docOrder;

  /**
   * The source for this iterator.
   */
  private DTMAxisIterator _source;

  /**
   * A reference to a filter object.
   */
  private final CurrentNodeListFilter _filter;

  /**
   * An integer array to store nodes from source iterator.
   */
  private IntegerArray _nodes = new IntegerArray();

  /**
   * Index in _nodes of the next node to filter.
   */
  private int _currentIndex;

  /**
   * The current node in the stylesheet at the time of evaluation.
   */
  private final int _currentNode;

  /**
   * A reference to the translet.
   */
  private AbstractTranslet _translet;

  public CurrentNodeListIterator(DTMAxisIterator source,
      CurrentNodeListFilter filter,
      int currentNode,
      AbstractTranslet translet) {
    this(source, !source.isReverse(), filter, currentNode, translet);
  }

  public CurrentNodeListIterator(DTMAxisIterator source, boolean docOrder,
      CurrentNodeListFilter filter,
      int currentNode,
      AbstractTranslet translet) {
    _source = source;
    _filter = filter;
    _translet = translet;
    _docOrder = docOrder;
    _currentNode = currentNode;
  }

  public DTMAxisIterator forceNaturalOrder() {
    _docOrder = true;
    return this;
  }

  public void setRestartable(boolean isRestartable) {
    _isRestartable = isRestartable;
    _source.setRestartable(isRestartable);
  }

  public boolean isReverse() {
    return !_docOrder;
  }

  public DTMAxisIterator cloneIterator() {
    try {
      final CurrentNodeListIterator clone =
          (CurrentNodeListIterator) super.clone();
      clone._nodes = (IntegerArray) _nodes.clone();
      clone._source = _source.cloneIterator();
      clone._isRestartable = false;
      return clone.reset();
    } catch (CloneNotSupportedException e) {
      BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,
          e.toString());
      return null;
    }
  }

  public DTMAxisIterator reset() {
    _currentIndex = 0;
    return resetPosition();
  }

  public int next() {
    final int last = _nodes.cardinality();
    final int currentNode = _currentNode;
    final AbstractTranslet translet = _translet;

    for (int index = _currentIndex; index < last; ) {
      final int position = _docOrder ? index + 1 : last - index;
      final int node = _nodes.at(index++);        // note increment

      if (_filter.test(node, position, last, currentNode, translet,
          this)) {
        _currentIndex = index;
        return returnNode(node);
      }
    }
    return END;
  }

  public DTMAxisIterator setStartNode(int node) {
    if (_isRestartable) {
      _source.setStartNode(_startNode = node);

      _nodes.clear();
      while ((node = _source.next()) != END) {
        _nodes.add(node);
      }
      _currentIndex = 0;
      resetPosition();
    }
    return this;
  }

  public int getLast() {
    if (_last == -1) {
      _last = computePositionOfLast();
    }
    return _last;
  }

  public void setMark() {
    _markedNode = _currentIndex;
  }

  public void gotoMark() {
    _currentIndex = _markedNode;
  }

  private int computePositionOfLast() {
    final int last = _nodes.cardinality();
    final int currNode = _currentNode;
    final AbstractTranslet translet = _translet;

    int lastPosition = _position;
    for (int index = _currentIndex; index < last; ) {
      final int position = _docOrder ? index + 1 : last - index;
      int nodeIndex = _nodes.at(index++);         // note increment

      if (_filter.test(nodeIndex, position, last, currNode, translet,
          this)) {
        lastPosition++;
      }
    }
    return lastPosition;
  }
}
